It is estimated that more than 150 million people in the USA use corrective eye wear for refractive errors (Prevent Blindness America, 2002). Contact lenses represent an increasingly popular and convenient solution to correct defective vision such that the contact lens market has a growth of approximately 20% year over year, and sales have grown from $16 million in 1998 to an expected $184 million in 2003. Contact lenses by their very nature are small, delicate and easily damaged, and this leads to problems associated with handling and insertion for a great many users. Installation and removal of contact lenses can be physically cumbersome and time consuming, and the majority of users are known to experience difficulties when they first start wearing contact lenses.
Many people go on to find the insertion and removal of contact lenses a natural thing to do, but a significant proportion of people are believed to have continuing difficulties/problems associated with contact lens insertion/removal. It is widely perceived within the industry that there is a requirement for a solution to overcome the problems associated with manipulation, insertion and removal of contact lenses.
Hygiene can also pose a problem with regard to the wearing of contact lenses-in the event that a contact lens is dropped during insertion into or removal from the eye it may become contaminated with particulate matter (e.g. dirt) or micro-organisms (e.g. bacteria), which can cause infections, discomfort, and damage to the eye. There is also a risk that a contact lens may become contaminated through contact with the skin of a finger or the palm of the hand. A variety of microorganisms are involved in causing eye infections, but the most commonly isolated organisms are Serratia, Pseudomonas and Acinetobacter (from contaminated sterilizing and washing solutions) and staphylococci (from direct handling of contact lenses). In order to maintain good ocular hygiene it is important that a contact lens user washes their hands prior to insertion/removal of a contact lens, and that the contact lenses are cleaned properly in accordance with the manufacturers instructions.
Indeed, deviation from recommended wear and care procedures are the prime factors involved in contraction of Acanthamoeba keratitis, a serious and painful condition which may cause long-term damage to the eye. Cleaning and disinfection of contact lenses can thus be time consuming and impractical, particularly when a user does not have a ready means available to clean their hands prior to handling their contact lenses e.g. whilst travelling. Survey evidence suggests that 75% of existing contact lens users reported that they would use an apparatus which would not only insert/remove their lenses but also clean and store them.
Prior art contact lens insertion and removal devices include U.S. Pat. No. 4,201,408, U.S. Pat. No. 4,427,226, and WO 99/21519. U.S. Pat. No. 4,201,408 discloses a device having a cup to receive a contact lens, the cup having a hole connected to a tube. The tube serves to apply negative pressure to the contact lens in order to pick it up, and positive pressure to facilitate discharge of the contact lens onto the eyeball. The tube also provides a light source, visualized as a bright spot of light which can serve as a target by a user, thereby making the process of contact lens insertion/removal easier. A means is provided to distort the cup and the contact lens which aids removal of a contact lens from the eye.
U.S. Pat. No. 4,427,226 discloses a device combining a means to position or remove a contact lens combined with a means to keep the upper and lower eyelids open. Using one hand, the eyelids are retained open using eyelid engaging means, and the contact lens is positioned or removed using the other hand and a pair of flexible tweezers.
WO 99/21519 discloses a package containing a contact lens stored in saline solution. The package comprises an applicator for applying the contact lens to the eye, thereby circumventing the requirement for a user to physically pick up the contact lens and place it on their palm prior to insertion onto the eyeball. By removing contact between fingers and the contact lens, the chances of contaminating the contact lens by a user are thereby considerably reduced, and good ocular hygiene is maintained.
Prior art devices are primarily used for the insertion and/or removal of contact lenses from the eye. The devices, although minimizing contact with skin and therefore the risks of contamination of a contact lens, still require the use of both hands, typically with one hand holding open the eyelids, and the other hand inserting the contact lens through the use of an applicator or tweezers. The application step, although facilitated through the use of tweezers or an applicator, can still be problematic since it invariably requires a degree of skill and dexterity by the user-a good aim and appropriate use of force is required to position a contact lens on the eyeball. Importantly, none of the prior art devices are designed for cleaning contact lenses—the contact lenses may be removed and stored using the prior art devices, but cleaning of a contact lens prior to storage invariably involves manual (i.e. fingertip) “scouring” or “scrubbing” of the contact lens with a cleaning solution typically comprising a detergent followed by rinsing with a sterile saline solution.